Fixture for radiographic examination of small objects having means for simultaneously rotating said objects



1967 J. G. SCHNEEMAN 3,295,435

FIXTURE FOR RADIOGRAPHIC EXAMINATION OF SMALL OBJECTS HAVING MEANS FOR SIMULTANEOUSLY ROTATING SAID OBJECTS 2 Sheets-Sheet 1 Filed NOV. 18, 1963 M R w 0.: W 0 NM E a m5 4 a m. @J a W Aw I f m v 5 fl n fiw .4

1967 J. G. SCHNEEMAN 3,296,435

FIXTURE FOR RADIOGRAPHIC EXAMINATION OF SMALL OBJECTS HAVING MEANS FOR SIMULTANEOUSLY ROTATING SAID OBJECTS Filed Nov. 18, 1963 2 Sheets-Sheet 2 INVENTOR. fusrw6. SCI-INAEM/JA/ WWW United. States Patent 3,296,436 FIXTURE FOR RADIUGRAPHIC EXAMINATIQN OF SMALL OBJECTS HAVING MEANS FOR SIMULTANEGUSLY ROTATING SAID OBJECTS Justin G. Schneeman, 7829 Industry Ave, Rivera, Calif. 90036 Filed Nov. 18, 1963, Ser. No. 324,344 Claims. (Cl. 250-51) This invention relates to radiography and specifically to a fixture to position small objects for making radiographs thereof.

The use of radiography in the non-destructive inspection of industrial items is well known and a variety of fixtures to hold and manipulate the item being inspected have been developed and are available. However, it appears that there are no such fixtures available for radiographing miniature and sub-miniature items, where the problems of how to hold and properly position the item in the X-ray beam have been attempted to be met by crude make-shift means.

In the radiography of generally tubular objects, no less than two views at right angles to .one another are desirable to clearly display the inner structure of the item. Miniature electronic components, such as diodes, transistors, and rectifiers, are extremely small and present problems in placement on or above a piece of film, holding during an exposure, and then rotating through 90 into position to make the desired second exposure at right angles to the first. The difiiculties of manipulation involved will be appreciated when it is recognized that a diode, for example, may be less than V of an inch in diameter and less than A of an inch long. Heretofore, these electronic components have been positioned manually and on an individual basis. Obviously, this mode of manipulation is quite cumbersome and time consuming since great care must be exercised to preserve the identification of each individual part and after the first photograph is taken, each part must individually be rotated 90 for taking the second photograph.

The present invention provides a fixture comprising an elongated rigid framework equipped with a plurality of small collets or chucks. These collets are adapted to rernovably receive leads of the electronic components which are to be examined and to support them in substantial parallelism and within a substantially common plane. The fixture, with the electronic components held therein, may be placed immediately adjacent the strip of film so that the components lie directly on or in very close proximity to the film or may be supported above the film by any suitable means, for magnification radiography. All of the collets are rotatably mounted in the fixture and interconnected by a common means for simultaneously rotating the collets for repositioning all of the components to make a second exposure. The collets are all further adapted for automatic adjustment to varying sizes of eads of different components and are also simultaneously opened or closed for the insertion and withdrawal of leads of the components through a cam mechanism.

A general object of my invention is to provide a holding fixture for the radiography of a multitude or plurality of small electronic components, which are handled as a group rather than individually, thus greatly reducing the amount of time involved in manipulating the components.

A further object of the invention is the provision of a fixture for a group of miniature or sub-miniature electronic components, that is adapted to position all of the components for radiography first in one plane and then in a normally related plane.

Yet another object of the invention is to provide a collet for a fixture of this class which automatically adjusts itself to the diameter of the lead of the component 3,296,436 Patented Jan. 3, 1967 to be inserted therein and securely grasps the lead so there can be no slippage between the lead and the collet as the collet is rotated through an arc for repositioning the component for radiographing in another plane.

The foregoing and other objects and advantages of my invention will be apparent from the following description of the presently preferred embodiment thereof, when taken in conjunction with the annexed drawings.

. FIGURE 1 is a perspective view of a fixture embodylIlg my invention, portions being cut away to reveal some interior details of construction, the fixture further being illustrated as holding a plurality of electronic components.

FIGURE 2 is a plan view showing the relationship of parts of the fixture when the-components are positioned for a first radiographic exposure.

FIGURE 2a is a schematic drawing illustrating the relative relationship of the electronic component, film and X-ray source when the parts of the fixture are arranged as in FIGURE 2.

FIGURE 3 is a plan view showing the relationship of the parts of the fixtureafter manipulation thereof to turn the electronic components for making a second radiographic exposure, angularly related to the first radiographic exposure.

FIGURE 3:: is a schematic drawing showing the change in relationship of the component relative to the X-ray source and film produced by the relationship of the parts of the fixture shown in FIGURE 3.

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 2.

FIGURE 5 is a sectional view similar to FIGURE 4 but with the parts of the fixture shown in a position for actuating the collets for release of the components therein. I

FIGURE 6 is a sectional view on the line 66 of FIG- URE 1.

FIGURE 7 is a partial sectional view, on a larger scale, showing details of configuration of the forward end of the collet.

The fixture is preferably made of aluminum, except for the springs, or other material which will not interfere with the image of the electronic parts to be held, at least as regards those portions of the fixture which will be in the field of the film. The fixture frame includes three elongated bars 11, 12, and 13. These bars are held in rigid parallel spaced relationship by a pair of straps 14 and 15 at opposite ends of the frame and secured to the bars by screws 16 or other suitable fastening means. As the frame is quite long in relation to its width, it is desirable to reinforce the bars 11, 12 and 13 against deflection intermediate the opposite ends of the frame. This may be accomplished, as shown in FIGURE 6, for each position at which such reinforcing is desired, by an elongated stud bolt 17 and a part of spacers 18 and 19. This bolt is passed through coaxially aligned holes formed in the bars 11, 12 and 13, through the collar 18, between the bars 11 and 12, and through the collar 19 between the bars 12 and 13. The hole through the bar 13 is counterbored as indicated at 20 to receive a nut 21 threadedly engaged with the low-er end of the bolt 17 and leave the bottom surface of the fixture (as viewed in FIGURE 6) uninterrupted. The upper end of the bolt 17 may protrude upwardly beyond the bar 11 and a nut 22 threaded thereon to clamp the bars 11, 12 and 13 against opposite ends of the spacers 18 and 19.

By way of example, the fixture shown in FIGURE 1 is provided with a total of 40 collet assemblies for holding any of a variety of electronic components. As these collet assemblies are identical, but one of them will be described in detail.

For each collet assembly, the bars 11, 12 and 13 are formed with coaxially aligned bores 23, 24 and 25 respectively. The chuck or collet comprises an elongated tubular jaw member 26 and a jaw or finger member 27 of generally semi-cylindrical configuration and of the same outer diameter as the tubular member 26. As best seen in FIGURE 5, the forward or lower end of the tubular member 26 is 'hemispherically relieved, as indicated by the notch 28, to slidably seat the finger member 27, which is complementary in configuration to the confronting portion of the forward end of the member 26. When the collet pieces 26 and 27 are in the locked or closed position illustrated in FIGURE 4, they together define a generally cylindrical assembly that is axially slidably reciprocable and rotatable in the aligned bores 23 and 24 of the bars 11 and 12.

In FIGURE 1, the fixture is illustrated as holding a group of diodes 30 and, at the far right, a transistor 31. Each diode has a coaxial opposite pair of leads 32 and these leads may vary in diameter, for example, from approximately of an inch to 4 of an inch. The collet pieces 26 and 27 at their forward ends are adapted to grasp and securely hold the leads of a desired range of diameters of leads. On the other hand, a component like the transistor 31 may not have a lead extending coaxially from its center or otherwise placed for convenient insertion into the collet. For example, the illustrated transistor 31 is generally hat-shaped in configuraiton and has three leads 33 protruding from one end only. For situreliability and less crimping of the lead will result by having a fiat seat on the notch 28.

The forward ends of the collet members 26 and 27 are both formed with external tapers 43 and 44 respectively, so as to be adapted for seating in a tapered upper end 45 of the hole formed in the lower bar 13. Thus, when the collet parts 26 and 27 are in the locked position of FIGURE 4, they are wedged towards one another. As there is sufficient clearance in the seat 45 of the lower bar 13 of the bore 24 in the intermediate bar 12 to permit the rocking action of the grip finger 27 in the notch 28, the grooves 40 and 42 in the forward end of the col-let parts automatically adjust to the diameter of lead inserted therebetween, while at the same time being wedged together with sufficient force to firmly secure the lead therein.

Each of the collet or chuck assemblies is opened or closed, and rotated by means of an actuating lever 46 having a bore at its inner end in which the tubular member 26 is received. A set screw 47 is mounted in an appropriately located tapper bore 48 formed in the wall of the inner end of arm 46 whereby the actuating lever 46 is clamped to the member 26. A coil spring 49 surrounds the tubular member 26 in the space between the upper bar ations such as this, I have provided an adapter 34 con sisting of a lead 35 having an end secured coaxi'ally to a disc 36. As is shown in FIGURE 4, the transistor 31 may be temporarily, preferably coaxially, secured to the disc 36 by a layer of a suitable adhesive 37 or double coated adhesive tape and thus supported in alignment with the lead 35 that is held between the collet parts 26 and 27.

For clarity of illustration, the diameterof the leads illustrated in the drawings, and of the electronic components as a whole, have been exaggerated as have also the configuration of those portions of the collet parts 26 and 27 which come into contact with the lead.

The manner of operation of the collet assembly can best be seen from FIGURES 4, 5 and 7. The tips of the collet pieces 26 and 27 are formed with internal tapers 38 and 39, respectively, for guiding the lead to be secured, in this case the lead 35 of the adapter 34, into the collet. The longitudinally extending surface of the notch 28 in the tubular member 26 lies in a diametral plane of the member and at its forward end is formed with a axial extending groove 40, which could be V- shaped, but is preferably of semi-circular cross-sectional configuration with a diameter approximately the same as the greatest of the range of diameters of lead to be inserted into the collet. The grip finger 27 has an inner face 41 confronting the flat diametral face of the shoulder or notch 28 of the other collet member 26, but which is convex in a direction longitudinally of the collet assembly, from end to end, so as to have a slight rocking action on the notch 28. At its forward end, the inner face of the grip finger 27 is formed with an axial groove 42 which could also be V-shaped, but is preferably of armate cross-sectional configuration and defining a slightly tapered orifice or bore, for the reception of the lead 35, within the groove 40. Due to the slight convexity on the inner face 41 of the grip finger 27, the groove 42 is not of uniform cross-sectional configuration, but is of varying depth through its length, being shallowest at its forward end and its greatest depth has a diameter which is preferably the same as the diameter of the groove 40. For example, the groove 40 may have a radius and uniform depth of 0.020 inch while the groove 42, also of 0.020 radius, may vary in depth from 0.001 inch to 0.020 inch. Then, the tapered orifice defined by the groove would adjust automatically to and grip lead diameters ranging from 0.021 inch to 0.040 inch by the finger 27 rocking on the notch 28. The range may be increased by making the seat of the notch 28 also convex but greater 11 and the inner end of the actuating lever and normally biases the tubular member 26 downwardly for seating both the member 26 and grip finger 27 in the taper seat 45. All of the levers 46 at their outer ends are pivotally interconnected to an actuating bar 51 by means of pins 52. As will be seen from a comparison of FIG- URES 2 and 3, shifting of the actuating bar 51 between the two positions shown efiects rotation of each collet assembly to a desired arc, in this case whereby the I electronic components held in the collets undergo a corresponding rotation of about their own longitudinal axis so as to be positionable in angularly related planes for radiography in several planes.

For opening and closing the col-lets, the fixture frame mounts a cam mechanism such as is seen in FIGURES 4 and 5. A pair of bearing blocks 54 and 55 are secured to the frame straps 14 and 15 by suitable fasteners such as bolts 56. A camming bar 57, here of cylindrical configuration, is supported in the blocks 54 and '55 by trunnions 58 and 59 journalled in suitable coaxially related bores formed in the bearing blocks. These trunnions have their common axis ec-centrically disposed or in crank pin relationship to the axis of the camming bar 57 whereby rotation of the camming bar on the axis of the trunnions is translated into reciprocating movement of the collet assemblies to effect their opening or closing.

In order to turn the camming bar 57, the trunnion 59 projects beyond the block 55 and has a ring 60 coaxially secured thereto as by means of a set screw (not shown). This ring is provided with an operating handle 61 projecting radially therefrom. As it is desirable to have the camming bar 57 bear against the actuating levers 45 as closely as possible towards the inner fixed end of the levers, in order to avoid bending them unduly, a pair of stop pins 62 and 63 project in an axial direction from the ring 60 such that the are through which the camming bar 57 swings is disposed inwardly of the pivotal axis of the camming bar and more closely to the inner ends of the actuating levers 45.

The frame of the fixture is largely enclosed by a generally channel shaped cover 65 having a rear wall 66 that spans the width of the fixture and an abbreviated front wall 67. A plurality of screws 68, passing through the rear wall of the cover into suitably tapped bores in the bars 11, 12 and 13, hold the cover in place. The front wall 67 of the cover 65 is abbreviated to leave sufiicie-nt clearance between its lower edge and the upper face of the intermediate bar 12 to provide an adequate range of movement of the actuating levers 45 to insure proper opening and closing of the collets. Another cover plate 69 is held in place by suitable screws 70 on the front of the fixture frame, this cover plate spanning the lower bar 13 and intermediate bar 12. As is shown in FIGURE 1, the cover plate 69 is imprinted or otherwise provided with numerals 71, each of which is located adjacent a collet assembly. The numerals 71 may be leaded or otherwise adapted to be radiographed whereby their images will appear on the film along with the image of the corresponding electronic component held in the corresponding collet.

In using the fixture, when it is desired to load it with electronic components, such as the diodes 30, or components each of which is mounted on adapters 34, the handle 61 is turned to move to the position of FIGURE 5. This effects revolution of the camming bar 57 around the axis of the trunnions 58 and 59 whereby all of the actuating levers 45 are moved upwardly against the force of the springs 49. The tubular member 26 as a result is lifted out of the seat 45 while the grip finger 27 may tend to stay seated within the seat. The lead of the component or adapter is then inserted through the bore 25 and by virtue of the tapers 38 and 39 is centered and received in the grooves 40 and 42 of the two parts of the collet.

The handle 61 is then turned to the position shown in FIGURE 4, allowing the tubular member 26 and grip finger 27 to be spring biased back into the taper seat 45 and wedged together. Then, due to the longitudinally convex inner face 41 of the grip finger 27, the grip finger will rock on the seat provided therefor, in the notch 28 of the member 26 until the lead of the component is clamped in that cross-section of the tapered orifice, defined by the grooves 40 and 42, which equals the diameter of the lead.

After the fixture has been loaded with electronic components, the bar 51 is then pulled to one extreme position, as for example the position shown in FIGURE 2. The loaded fixture is then ready to be placed in the desired relationship to a source 72 of X-rays and film 73, as illustrated in FIGURE 2a. The exposure may then be made after which the bar 51 is shifted to the other extreme shown in FIGURE 3, as a result of which all of the components are revolved on their own longitudinal axes through an arc of 90. The change in position of the components is represented by the change in the position of the schematic reference point 74 illustrated in FIG- URES 2a and 3a. Then the components are all disposed for making a second radiographic exposure through diametral planes of the component turned 90 from the first exposure. Various devices may be employed in the fixture for limiting rotation of the collets and components to 90. The means illustrated here is a width of the levers 46 such that rotation is limited to 90, in view of the parallelogram relationship of the levers.

While the presently preferred embodiment of my invention has been illustrated and described above, it will be appreciated by those skilled in the art that various modifications and changes may be made. Accordingly, I do not mean to be limited to the various details of con struction hereinabove set forth, but only by the spirit and scope of the following claims.

I claim:

1. A fixture for holding leads of small objects for radiographic examination of the objects comprising:

a frame;

a plurality of holding means rotatably mounted on said frame in a substantially common plane and each adapted to removably support a lead and object in said plane, each of said holding means being rotatable on the axis of said lead; and

a means connected to all of said holding means for rotating all of said holding means whereby to rotate the leads and objects held therein for disposing angularly related planes of said objects within said common plane.

2. A fixture for holding leads of small objects for radiographic examination of the objects comprising:

an elongated rigid framework;

a plurality of collets mounted in said framework in substantially coplanar relationship and for limited rotation about their individual axes, each of said collets having a plurality of openable and closable jaws for removably clamping the lead of an object therein coaxially with said collet;

actuating means operatively associated with all of said collets adapted for opening and closing said jaws of said collets in response to movement of said actuating means; and

an elongated member connected to each of said collets and adapted for rotating all of said collets through equal arcs in response to movement of said elongated member whereby angularly related planes of said objects can be disposed in said common plane.

3. A fixture for holding leads of small objects for radiographic examination of the objects comprising:

an elongated rigid frame;

a plurality of substantially parallel collet assemblies mounted in said frame in a substantially common plane, each of said assemblies comprising a pair of opposed jaw members supported in said frame for rotation about the longitudinal axis of said assembly and for limited axial reciprocal movement, the contacting surfaces of said jaw members having axial grooves formed therein adapted for clamping the lead of an object when said jaw members are clamped together whereby to support said lead and object coaxially with said assembly;

a plurality of collet seats formed in said frame, each of said seats being disposed coaxially with one of said assemblies, each of said seats and forward ends of the jaw members of the collet assembly associated therewith having engageable surfaces adapted to clamp said jaw members together when said jaw members are urged forwardly into said seat;

spring means for each of said collet assemblies interposed between said frame and the assembly for normally biasing said pair of jaw members into said seat; and

cam means including an elongated member mounted on said frame adjacent all said collet assemblies, said cam means being adapted to translate rotation of said elongated member into movement of all said collet assemblies to lift at least one jaw member of each of said collet assemblies from said seats whereby to open said jaw members for the removal and insertion of leads of said objects.

4. A fixture as set forth in claim 3 in which all of said collet assemblies are pivotally interconnected to an elongated handle for simultaneously effecting rotation of all said assemblies about their individual longitudinal axes.

5. A fixture as set forth in claim 3 in which said contacting surface of one of said jaw members is longitudinally convex for rocking on the other of said contacting surfaces, the grooves in both said surfaces being arcuate in cross-sectional configuration and of the same radius, said groove of said other jaw member being uniformly semi-cylindrical throughout its length and said groove of said one jaw member uniformly varying in depth through its length, said grooves together defining a tapered orifice adapted for clamping leads of varying diameters.

References Cited by the Examiner UNITED STATES PATENTS 1,938,310 12/1933 Appelberg et al 269-153 2,400,314 5/1946 Obecny 269153 2,655,826 10/1953 Goldsby 269-254 2,662,433 12/1953 Braun 269153 RALPH G. NILSON, Primary Examiner. A. L. BIR H; A sistant Examiner. 

2. A FIXTURE FOR HOLDING LEADS OF SMALL BJECTS FOR RADIOGRAPHIC EXAMINATION OF THE OBJECTS COMPRISING: AN ELONGATED RIGID FRAMEWORK; A PLURALITY OF COLLETS MOUNTED IN SAID FRAMEWORK IN SUBSTANTIALLY COPLANAR RELATIONSHIP AND FOR LIMITED ROTATION ABOUT THEIR INDIVIDUAL AXES, EACH OF SAID COLLETS HAVING A PLURALITY OF OPENABLE AND CLOSABLE JAWS FOR REMOVABLY CLAMPING THE LEAD OF AN OBJECT THEREIN COAXIALLY WITH SAID COLLET; ACTUATING MEANS OPERATIVELY ASSOCIATED WITH ALL OF SAID COLLETS ADAPTED FOR OPENING AND CLOSING SAID JAWS OF SAID COLLETS IN RESPONSE TO MOVEMENT OF SAID ACTUATING MEANS; AND AN ELONGATED MEMBER CONNECTED TO EACH OF SAID COLLETS AND ADAPTED FOR ROTATING ALL OF SAID COLLETS THROUGH EQUAL ARCS IN RESPONSE TO MOVEMENT OF SAID ELONGATED MEMBER WHEREBY ANGULARLY RELATED PLANES OF SAID OBJECTS CAN BE DISPOSED IN SAID COMMON PLANE. 